function Transition() {
};

Transition.instance = function(title, source, target, position, mode, length) {
  var transition = { title: title,
                     source: source,
                     target: target,
                     position: position,
                     mode: mode,
                     length: length,
                     validate: function(produce, user, date, options) { return (position == user.type); },
                     operate: null
                   };
  transition.operate = function(pos, callbackFunc, produce, user, date, options) { DlmanageUtils.operate(transition, pos, callbackFunc, produce, user, date, options); };
  return transition;
};
